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Horizontal and continuous beds. Folded beds. Tilted beds. Discordant relationships. Bedding above the discordance. Discordance (nonconformity). Tilted bedding below discordance (nonconformity). Bedding and lamination - Laminated bedding - Graded bedding - Massive (structureless) bedding
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Discordant relationships Bedding above the discordance Discordance(nonconformity) Tilted bedding below discordance(nonconformity)
Bedding and lamination- Laminated bedding- Graded bedding- Massive (structureless) bedding Bedforms Irregular stratification Groove cast; striations, bounce, brush, prod, and roll mark Flute cast Load cast Mudcracks and syneresis cracks Sedimentary structures Stratification and bedforms: Bedding-plane markings: Other structures:- Sedimentary sills and dykes
Bedding • Beds, or strata are tabular or lenticular layers of sedimentary rock that have lithologic, textural, or structural unity that clear distinguishes them from layers above and bellow. • Groups of similar beds or cross beds are called bedsets.
Description of bedding • Lateral continuity • Termination- merging of bedding planes (pinch-out)- lateral gradation of composition (die out)- meeting of crosscutting features such as channel or unconformity • Parallel bedding • Wavy bedding
Mechanisms of bedding formation • sedimentation from suspension • horizontal accretion from a moving bed load (bed load is a part of the stream load that moves on or immediately above the stream bed; stream load is all material that is transported by a stream) • encroachment into the lee of an obstacle.
Graded bedding • Gradual change of grain size within a bed • Commonly produced by turbidity currents • Helps to determine the base (lower surface) and the top (upper surface) of a bed
TOP Sandstones Conglomerates Up The Section BOTTOM GRADED BEDDING
Bedforms – structures of the surface of a bed • Cross-bedding • Ripple cross-lamination • Flaser and lenticular bedding
Assymetric flow ripples from Vermillon River (Asimetrik akıntı ripple’ları. Vermillon Nehri.)
Cross stratification • Cross stratification from Jurassic age Navajo sandstones. Flow direction is from left to right • Cross str. occurs because of overlaping of ripplemarks.
Tabular cross bed(düzlemsel) Convulute crs. Bed.(Kama şeklinde) Hummocky crs bed.
Irregular stratification • Convolute bedding and lamination • Flame structures • Channels • Scour-and-fill structures
Penecontemporaneous folds in the Maranosa Arenaci (Italian Apennines)
Bedding-plane markings • Groove cast; striations, bounce, brush, prod, and roll mark • Flute cast • Load cast • Mudcracks and syneresis cracks
Grooves(Oluk yapıları) Striations (Buzul kertikleri)
Flute marks Load casts Groove casts
Load structures They form prior to lithification where a denser sand lies on top of less dense mud and a disturbance by a storm or an earthquake causes blobs of sand to sink into the underlying mud.
Ball-and-pillow structures protrusions extending downward from a sand layer into an underlying mud or very fine sand layer
Carbonate nodule within shales Nodule : A small rounded mass in a contrasting rock matrix.
Bioturbation – horizontal bedding is disturbed by burrow and boring channels of fossils
CURRENT DIRECTION CROSSBEDDINGS Cross-bedding Bedding